In the manufacture of wet laid facial tissue, bathroom tissue or paper towels, the fibrous web may be creped in order to provide it with the desired characteristics, such as softness and bulk. The wet creping process involves adhering the web to a rotating creping cylinder, such as a Yankee dryer, and then removing the adhered web with a doctor blade. The doctor blade impacts the web causing the web to buckle and in doing so ruptures some of the fiber-to-fiber bonds within the web. The severity of this creping action depends upon a number of factors, including the degree of adhesion between the web and the surface of the creping cylinder. Greater adhesion generally causes increased softness. In order to increase the adherence of the fibrous web to the Yankee dryer, a creping adhesive is usually sprayed onto the surface of the creping cylinder to supplement any natural adhesion the web may have when applied to the creping cylinder.
A wide variety of creping adhesives are known in the art. The paper industry's demand for faster paper machine speeds, less down time due to doctor blade changes and paper breaks, and softer and more uniform paper necessitates development of new and better creping adhesives. Desirable qualities for new and better creping adhesives that will improve paper machine runnability include: increased adhesion, dispersibility, uniform coating, and resistance to bleach out.